Door material for evaporator.

[vach50]

I have a homemade evaporator that has worked well. I am having a problem with the door however. Basically it is insulation sandwiched between two plates of mild steel. The steel on the fireside does not hold up to the heat. It spaulds, bubbles and flakes off. I can see insulation thru it. I need to replace it again and want to find either a better material or better method. I know cast iron doors are standard, I can't find anything that fits my opening. Any ideas? Thanks.

[vach50]

I've done more searching on this. I can't find a place for flat cast iron plate. Of the common stainless steels, looks like 304 can take the most heat. I might just go with that. Still would be interested in what others have done or think might work.

[maple maniac65]

Can you put ceramic blanket on the fire side door to insulate it

[DocsMapleSyrup]

I have ceramic blanket on the inside of the door which is exposed to the fire. It holds up fine as long as you are not jamming the door shut against the wood.

[AndrewsofBow]

Bolt on ceramic blanket with fender washers, it holds up pretty well.

[Paperman]

In commercial boilers we use a hard refractory in all doors. Its like cement but made to take the heat. If you can fabricate a door out of 1-1/2 angle you can install 3/4" of hard insulating board and face it with 3/4" of castable refractory or use split bricks.